1. Field of the Invention
The present invention relates to a wire discharge device for a wire cutting electric discharge machine, and, in particular, to a wire discharge device in which vibration in the wire is suppressed while the wire which has been used in the electric discharge process is being discharged, so that no wear occurs in conveyor belts and the discharge can be performed smoothly.
2. Description of the Prior Art
Conventionally, as a recovery means for recovering a wire used in an electric discharge process in a wire cutting electric discharge machine, a device in which the wire is interposedly supported between opposed top and bottom endless flat conveyor belts is used, and the belts are driven so that the wire is stretched and discharged to the outside of the machine.
In such a conventional wire electric discharge device of the type outlined above, since the part which interposedly supports the wire is limited to one position on the conveyor belts, the belts become worn from contact with the wire and a groove is formed therein, so that slip is produced between the wire and the belts and forced stretching is not possible. This problem results that the life of the belt is shortened, and when the wire is fed in, vibration occurs because of the wear in the belts.
Furthermore, since there is no control of the position of the wire which is interposedly supported in a conveying interval between the wire insertion section of the conveyor belt and the discharge end of the wire, the wire does not run in a straight line so that bending and distortion are produced in the wire being discharged. This leads to the inconvenience that the amount of wire which can be accommodated in the recovery box for recovering the wire outside the machine is reduced.
In view of the above drawbacks, this invention has been made. Therefore, an object of the present invention is to provide a wire discharge device for a wire cutting electric discharge machine which comprises a conveyor belt mechanism with a feed roller and discharge rollers provided in the front and rear sides of the member, respectively, and a twist added to belts stretched between the conveying interval, of the conveyor belt mechanism wherein the wire can be conveyed in a straight line and wear in the belts does not give any affect to the discharge of the wire, whereby the replacement cycle of the belts can be extended.
According to the present invention, a wire discharge device for use in a wire cutting electric discharge machine comprises a feed roller which drives a wire used as the wire electrode, a belt conveyor mechanism which conveys the wire having been drive, and a pair of discharge rollers which pinches and feeds the wire to a recovery box. The conveyor mechanism has an upper belt conveyor and a lower belt conveyor disposed underneath the upper belt conveyor so that the wire is interposed between two belts, with the two belts twisted and in contact with each other over an interval. The wire used in the wire cutting electric discharge machine is thus conveyed to a recovery box through the conveyor mechanism by driving the feed roller and the pair of discharge rollers. Since the belts are twisted together, the wire interposed between the belts is conveyed in a straight line extended through the twisted conveying interval.
In the present invention having the structure as described above, the feeding, stretching and discharge actions of the wire can be smoothly carried out by driving the feed roller and the discharge rollers provided at the front and rear sides of the conveyor belt mechanism. Further, since the twist is added to the conveyor belts in the conveying interval of the conveyor belt mechanism, the force interposedly supporting the wire is increased so that the wire is aligned and can be made to run in a straight line.